// https://syzkaller.appspot.com/bug?id=1b8def838c616fcdf45f6a52434b9b089a743e2b // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include #include #include #include static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* uctx) { uintptr_t addr = (uintptr_t)info->si_addr; const uintptr_t prog_start = 1 << 20; const uintptr_t prog_end = 100 << 20; if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) && (addr < prog_start || addr > prog_end)) { _longjmp(segv_env, 1); } doexit(sig); } static void install_segv_handler() { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = SIG_IGN; syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8); syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8); memset(&sa, 0, sizeof(sa)); sa.sa_sigaction = segv_handler; sa.sa_flags = SA_NODEFER | SA_SIGINFO; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); } #define NONFAILING(...) \ { \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ } static void test(); void loop() { while (1) { test(); } } struct thread_t { int created, running, call; pthread_t th; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); } return 0; } static void execute(int num_calls) { int call, thread; running = 0; for (call = 0; call < num_calls; call++) { for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); pthread_create(&th->th, &attr, thr, th); } if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) { th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); struct timespec ts; ts.tv_sec = 0; ts.tv_nsec = 20 * 1000 * 1000; syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts); if (running) usleep((call == num_calls - 1) ? 10000 : 1000); break; } } } } #ifndef __NR_mmap #define __NR_mmap 192 #endif #ifndef __NR_socket #define __NR_socket 359 #endif #ifndef __NR_connect #define __NR_connect 362 #endif #ifndef __NR_close #define __NR_close 6 #endif #ifndef __NR_dup2 #define __NR_dup2 63 #endif #undef __NR_mmap #define __NR_mmap __NR_mmap2 long r[3]; uint64_t procid; void execute_call(int call) { switch (call) { case 0: syscall(__NR_mmap, 0x20000000, 0xe77000, 3, 0x32, -1, 0); break; case 1: r[0] = syscall(__NR_socket, 0xa, 2, 0); break; case 2: r[1] = syscall(__NR_socket, 0x18, 1, 1); break; case 3: NONFAILING(*(uint16_t*)0x20e71000 = 0x18); NONFAILING(*(uint32_t*)0x20e71002 = 1); NONFAILING(*(uint32_t*)0x20e71006 = 0); NONFAILING(*(uint32_t*)0x20e7100a = r[0]); NONFAILING(*(uint16_t*)0x20e7100e = 3); NONFAILING(*(uint16_t*)0x20e71010 = 0); NONFAILING(*(uint16_t*)0x20e71012 = 3); NONFAILING(*(uint16_t*)0x20e71014 = 0); NONFAILING(*(uint16_t*)0x20e71016 = 0xa); NONFAILING(*(uint16_t*)0x20e71018 = htobe16(0x4e22 + procid * 4)); NONFAILING(*(uint32_t*)0x20e7101a = 3); NONFAILING(*(uint8_t*)0x20e7101e = 0xfe); NONFAILING(*(uint8_t*)0x20e7101f = 0x80); NONFAILING(*(uint8_t*)0x20e71020 = 0); NONFAILING(*(uint8_t*)0x20e71021 = 0); NONFAILING(*(uint8_t*)0x20e71022 = 0); NONFAILING(*(uint8_t*)0x20e71023 = 0); NONFAILING(*(uint8_t*)0x20e71024 = 0); NONFAILING(*(uint8_t*)0x20e71025 = 0); NONFAILING(*(uint8_t*)0x20e71026 = 0); NONFAILING(*(uint8_t*)0x20e71027 = 0); NONFAILING(*(uint8_t*)0x20e71028 = 0); NONFAILING(*(uint8_t*)0x20e71029 = 0); NONFAILING(*(uint8_t*)0x20e7102a = 0); NONFAILING(*(uint8_t*)0x20e7102b = 0); NONFAILING(*(uint8_t*)0x20e7102c = 0 + procid * 1); NONFAILING(*(uint8_t*)0x20e7102d = 0xbb); NONFAILING(*(uint32_t*)0x20e7102e = 4); syscall(__NR_connect, r[1], 0x20e71000, 0x32); break; case 4: r[2] = syscall(__NR_socket, 0x18, 1, 1); break; case 5: syscall(__NR_close, r[0]); break; case 6: syscall(__NR_dup2, r[2], r[1]); break; } } void test() { memset(r, -1, sizeof(r)); execute(7); } int main() { for (procid = 0; procid < 8; procid++) { if (fork() == 0) { install_segv_handler(); for (;;) { loop(); } } } sleep(1000000); return 0; }